1,639 research outputs found

    Intermolecular Potentials of Argon, Methane, and Ethane

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    The viscosities of argon, methane, and ethane are reported over a temperature range from ∼210°K to ∼475°K. In conjunction with second virial coefficient data, the viscosities have been employed to estimate the potential parameters for an Exp:6 potential. For the spherically symmetric molecules a single set of parameters served to reproduce the equilibrium and transport properties with serviceable accuracy. For ethane the procedure failed, and this failure was taken as further evidence for the fundamental inadequacy of the assumptions of central forces and elastic collisions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70109/2/JCPSA6-28-6-1152-1.pd

    Neutrino-nucleus cross section within the extended factorization scheme

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    The factorization scheme, based on the impulse approximation and the spectral function formalism, has been recently generalized to allow the description of electromagnetic nuclear interactions driven by two-nucleon currents. We have extended this framework to the case of weakly charged and neutral currents, and carried out calculations of the double-differential neutrino-carbon and neutrino-oxygen cross sections using two different models of the target spectral functions. The results, showing a moderate dependence on the input spectral function, confirm that our approach provides a consistent treatment of all reaction mechanisms contributing to the signals detected by accelerator-based neutrino experiments

    Metachronous bladder metastases from renal cell carcinoma: a case report and review of the literature

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    INTRODUCTION: adrenal gland, parotid gland, pharynx, eye and bladder are rare localizations of metastases of renal cell carcinoma (RCC). We report a case of metachronous RCC metastases to the bladder in a patient with a medical history of transitional cell carcinoma (TCC) of the bladder. MATERIALS AND METHODS: a case study and review of the relevant literature are presented. RESULTS: during a follow-up cystoscopy examination following treatment of TCC, a single 5-mm lesion was detected and endoscopically resected. The histology of the resected sample was confirmed to be RCC, comparable to a primary kidney cancer and not recurrent TCC. CONCLUSION: the patient had a probability of metastases three years after nephrectomy of 62.9%. Survival rates following single metastasectomy are 60% and 38% at three and five years, respectively; metachronous diagnosis has a better prognosis than synchronous. During RCC follow-up, each lesion should be considered as a possible metastasis of RCC

    Chitosan-alginate microparticles of Andrographis paniculata and Annona muricata extracts for Controlled Release

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    This study investigates the properties of microparticles prepared from Andrographis paniculata (AP) and Annona muricata (AM) aqueous extracts for controlled release. Extracts obtained by maceration of the dried powdered plant leaves were microencapsulated by counterion coacervation method. Microcapsules were characterized using Fourier-transform infrared-spectroscopy (FTIR), x-ray difractometry (XRD) and differential scanning calorimetry (DSC).In vitro release studies were carried out at pH 1.2 for 2 h and 6.8 for a further 10 h. Release was monitored at274 and 230 nm for AM and AP, respectively. Encapsulation efficacy was less than 52% for AP and 70% for AM. In vitro drug release at pH 1.2 showed less than 40% release from the microcapsules after 2h while over 90% of extract was released after 6h at pH 6.8. Conventional capsules released the content within 1 h in simulated gastric fluid. FTIR, XRD and DSC results indicate the stable character of the extract within the microcapsules. Microencapsulation with chitosan- alginate controlled the release of Andrographis paniculata (AP) and Annona muricata (AM) aqueous extracts

    Microencapsulated Garcinia kola and Hunteria umbellata Seeds Aqueous Extracts – Part 1: Effect of microencapsulation process.

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    Objective: This study investigates microcapsulated aqueous extracts of Garcinia kola (GK) and Hunteria umbellata (HU) seeds. Method: Extracts obtained after maceration of dried powdered seeds were prepared as microcapsules with chitosan-alginate by counterion coacervation method. Microcapsules were characterized using differential scanning calorimetry (DSC), x-ray diffractometry (XRD) and fourier transform infrared (FTIR) spectroscopy. In vitro release studies were carried out at pH 1.2 for 2 h and 6.8 for a further 10 h. Results: Between 20 and 50% extract release occurred from microcapsules after 2 h while conventional tablets released 100% after 1 h at simulated gastric pH. At pH 6.8, >80% of extract was released from microcapsules after 6 h. DSC revealed the presence of complex materials. XRD and FTIR showed stable character of the plant extracts within the microcapsules. Conclusion: Controlled release of aqueous extracts derived from these plants was achieved by microencapsulation and therefore can be developed as suitable delivery devices

    Nearly optimal solutions for the Chow Parameters Problem and low-weight approximation of halfspaces

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    The \emph{Chow parameters} of a Boolean function f:{1,1}n{1,1}f: \{-1,1\}^n \to \{-1,1\} are its n+1n+1 degree-0 and degree-1 Fourier coefficients. It has been known since 1961 (Chow, Tannenbaum) that the (exact values of the) Chow parameters of any linear threshold function ff uniquely specify ff within the space of all Boolean functions, but until recently (O'Donnell and Servedio) nothing was known about efficient algorithms for \emph{reconstructing} ff (exactly or approximately) from exact or approximate values of its Chow parameters. We refer to this reconstruction problem as the \emph{Chow Parameters Problem.} Our main result is a new algorithm for the Chow Parameters Problem which, given (sufficiently accurate approximations to) the Chow parameters of any linear threshold function ff, runs in time \tilde{O}(n^2)\cdot (1/\eps)^{O(\log^2(1/\eps))} and with high probability outputs a representation of an LTF ff' that is \eps-close to ff. The only previous algorithm (O'Donnell and Servedio) had running time \poly(n) \cdot 2^{2^{\tilde{O}(1/\eps^2)}}. As a byproduct of our approach, we show that for any linear threshold function ff over {1,1}n\{-1,1\}^n, there is a linear threshold function ff' which is \eps-close to ff and has all weights that are integers at most \sqrt{n} \cdot (1/\eps)^{O(\log^2(1/\eps))}. This significantly improves the best previous result of Diakonikolas and Servedio which gave a \poly(n) \cdot 2^{\tilde{O}(1/\eps^{2/3})} weight bound, and is close to the known lower bound of max{n,\max\{\sqrt{n}, (1/\eps)^{\Omega(\log \log (1/\eps))}\} (Goldberg, Servedio). Our techniques also yield improved algorithms for related problems in learning theory

    Synchronous collecting duct carcinoma and papillary renal cell carcinoma: A case report and review of the literature

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    The coexistence of multiple and synchronous primary neoplasms in the same organ (including kidney) has only rarely been described in the literature. We herein present a case of collecting duct carcinoma (CDC) combined with papillary renal carcinoma (RCC) having a 57-month disease-free survival. CDC is a rather rare and aggressive neoplasm of the kidney. Sharing probably the same embryological origin, synchronous or metachronous association with in situ or papillary transitional cell carcinoma (TCC) may be found; association with RCC has been only once reported in the literature. The high incidence of c-erbB-2 oncogene amplification in CDC further characterizes this tumor as a separate entity from renal cell carcinoma, and shows some genetic characteristics in common with TCC. The histohgical diagnosis of Bellini CDC can be confirmed by the positive immuno-histochemical staining with a collecting duct marker and distal tubule marker and negative staining with a proximal tubule marker

    Surgical resection is superior to TACE in the treatment of HCC in a well selected cohort of BCLC-B elderly patients—A retrospective observational study

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    Simple Summary Hepatocellular carcinoma (HCC) is the most common primary liver malignancy. Liver transplantation (LT) and surgical resection (SR) are currently the primary treatments with curative intent. Nevertheless, more than two-thirds of patients are elderly and, therefore, excluded from LT; while, according to the Barcelona Clinic Liver Cancer (BCLC) system, SR should only be offered to a small group of patients with early stage HCC. The identification in stage B of an intermediate subgroup of patients that fulfill the criteria for surgery may play an important role in the implementation of potentially curative treatments. Hepatocellular carcinoma (HCC) usually develops in cirrhotic liver, with high recurrence rates. However, considering its increasing detection in non-cirrhotic liver, the choice of treatment assumes particular relevance. This study aimed to investigate outcomes of patients among BCLC stages and enrolled for surgical resection (SR) according to a more complex evaluation, to establish its safety and efficacy. A total of 186 selected HCC patients (median age 73.2 yrs), submitted to SR between January 2005 and January 2021, were retrospectively analyzed. Of which, 166 were staged 0, A, B according to the BCLC system, while 20 with a single large tumor (>5 cm) were classified as stage AB. No perioperative mortality was recorded; complications occurred in 48 (25.80%) patients, and all but two were Clavien-Dindo grade I-II. Median follow-up was 9.2 years. Subsequently, 162 recurrent patients (87,1%) were selected for new treatments. Comparable overall survival rates (OS) were observed at 1, 3, 5, and 10 years in 0, A, B and AB stages (p = 0.2). Eventually, the BCLC-B group was matched to 40 BCLC-B patients treated (2015-2021) with TACE. Significant differences in baseline characteristics (p <0.0001) and in OS were observed at 1 and 3 years (p <0.0001); a significant difference was also observed in oncological outcomes, in terms of the absence, residual, or relapse of disease (p <0.05). Surgery might be a valid treatment in HCC for patients affected by chronic liver disease in a condition of compensation, up to BCLC-B stage. Surgical indication for liver resection in case of HCC should be extensively revised

    Influence of chemical doping and hydrostatic pressure on the magnetic properties of Mn1-xFexAs magnetocaloric compounds

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    CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORFAPERJ - FUNDAÇÃO CARLOS CHAGAS FILHO DE AMPARO À PESQUISA DO ESTADO DO RIO DE JANEIROFAPEMIG - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE MINAS GERAISFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOThis paper presents the results of an investigation of the magnetic and structural properties of Mn1-xFexAs compounds under hydrostatic pressure and chemical doping. The chemical doping was performed by using low Fe doping levels (x=0, 0.003, 0.006, 0.010, 0.015, and 0.018), which emulates the negative pressure effect on the crystal structure. The results of this approach were compared with the physical pressure effect (hydrostatic pressure from 0 to 2.2 kbar) on the Mn0.997Fe0.003As. Both approaches exhibit the same magnetic behaviors: the TC and saturation magnetization decrease as the pressure increases; for the highest pressure studied, an orthorhombic antiferromagnetic phase occurs below the critical temperature and coexists with the ferromagnetic hexagonal phase. The equivalence between hydrostatic pressure and chemical doping indicates that the Fe doping only causes structural deformation. In addition, we performed magnetic measurements at high temperature (up to 520 K) on the samples with x=0 and 0.003 in order to investigate the magnetic behavior above TC=310 K. These results, along with structural characterization, clearly show that between TC and Tt the system is a weak antiferromagnet with short-range order confined only in the ab plane. Finally, using the low- and high-temperature data, the magnetic phase diagrams of the compound under hydrostatic pressure and chemical doping were redrawn. © 2016 American Physical Society.This paper presents the results of an investigation of the magnetic and structural properties of Mn1-xFex As compounds under hydrostatic pressure and chemical doping. The chemical doping was performed by using low Fe doping levels (x = 0, 0.003, 0.006, 0.010, 0.015, and 0.018), which emulates the negative pressure effect on the crystal structure. The results of this approach were compared with the physical pressure effect (hydrostatic pressure from 0 to 2.2 kbar) on the Mn0.997Fe0.003As. Both approaches exhibit the same magnetic behaviors: the T-C and saturation magnetization decrease as the pressure increases, for the highest pressure studied, an orthorhombic antiferromagnetic phase occurs below the critical temperature and coexists with the ferromagnetic hexagonal phase. The equivalence between hydrostatic pressure and chemical doping indicates that the Fe doping only causes structural deformation. In addition, we performed magnetic measurements at high temperature (up to 520 K) on the samples with x = 0 and 0.003 in order to investigate the magnetic behavior above T-C = 310 K. These results, along with structural characterization, clearly show that between T-C and T-t the system is a weak antiferromagnet with short-range order confined only in the ab plane. Finally, using the low- and high-temperature data, the magnetic phase diagrams of the compound under hydrostatic pressure and chemical doping were redrawn.93519CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORFAPERJ - FUNDAÇÃO CARLOS CHAGAS FILHO DE AMPARO À PESQUISA DO ESTADO DO RIO DE JANEIROFAPEMIG - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE MINAS GERAISFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORFAPERJ - FUNDAÇÃO CARLOS CHAGAS FILHO DE AMPARO À PESQUISA DO ESTADO DO RIO DE JANEIROFAPEMIG - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE MINAS GERAISFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOSem informaçãoSem informaçãoSem informaçãoSem informaçãoSem informaçãoThe authors would like to thank to CNPq, CAPES, FAPERJ, FAPEMIG, FAPESP, and PROPPI-UFF for financial support
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